On 03.21 I lost connection to my FPV drone while flying over a lake. There were two people around the lake and I asked them after the incident if they saw anything. They said the drone fell into the lake. (More about it here: link )
I contacted the DJI support team and they said: "Based on the analysis of the available data, the flight was normal." And they offered me a 30% discount if I buy a new FPV drone.


After that I checked the logs different ways and I found a lot of strange things here and there.
Based on the Airdata flight log:

• Exiting GPS mode: Unknown Error
• Sensor system error
• Mode changed to Atti
  

Also I tried to check the dat file and I found some details there, but I'm totally unsure what do they mean (these values happened only at the end of the log):

• err_code:imu0_err: 65 (the same for imu1)
• err_code:imu0_fault: 2 (the same for imu1)
• err_code:imo0_act: 17 (the same for imu1)
  

Also a log file was exported from the dat and there were also some interesting things for example:
230.492 :   16404 [L-N_MIS]Fail to check mis 1. Reset
230.496 :   16404 [L-N_MIS]Fail to check mis 1. Reset
230.498 :   16404 [L-N_MIS]exit state: 1 -> 2, overtime.|
230.501 :   16404 [L-N_MIS]Fail to check mis 1. Reset
230.501 :   16404 [L-N_MIS]Exit mis 1. New mis 29
230.501 :   16404 [L-N_MIS]send cur mission exit data, mis:0, exit_reason:0.
230.501 :   16404 [L-N_MIS]Switch new mis 29 req 16 from mis 1 req 2
230.509 :   16405 [L-N_MIS]send cur mission exit data, mis:0, exit_reason:0.
230.509 :   16405 [L-N_MIS]Switch new mis 2 req 1 from mis 29 req 16
230.509 :   16405 [L-FLYMODE]GPS2ATTI!Init atti dynscale scale 23.136307
230.522 :   16406 [L-RC]arm status change:255->0
230.540 :   16407 [L-WP2][AHRS] invalid pcov xy
230.561 :   16408 [L-WP2][AHRS] invalid pcov xy

Just to clarify, there were no errors on the screen before the video signal got lost. But seconds after the signal loss I saw the "Sensor system error" message popping up.

Hello there szacs93.  I am sorry to read and to know what happened to your DJI FPV. Since this unfortunate incident happened and you have lost the said drone. I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance. We have a team that will do there best to help you and give out the best resolution for the said issue. Again, I am sorry for your loss and thank you for your understanding.

How do you retrieve the flight logs on the DJI FPV?

Eclair29 Posted at 4-12 04:05
How do you retrieve the flight logs on the DJI FPV?

Take a look at this thread.